A known screw-drive conveying apparatus has a screw shaft row composed of a plurality of screw shafts concentrically arranged in a line and interlockingly rotating at a constant speed with respect to each other is provided along the traveling path of the conveying traveling body, and two driven front and rear rollers engaged with the screw shafts are provided to the conveying traveling body with a distance corresponding to the length of a screw discontinued space between the screw shafts, as described in Patent Document 1. In the screw-drive conveying apparatus of such configuration, a plurality of screw shafts having an easily manufactured length can be concentrically supported individually by bearings to construct a long screw shaft row, while the conveying traveling body can be continuously driven and travel irrespective of the existence of the screw discontinued space between the screw shafts.    Patent Document 1: Japanese unexamined patent application publication No. 2011-195261